1. Field of the Invention
The present invention relates to battery charging systems. More particularly, though not exclusively, the present invention relates to a method and apparatus for providing a smart power system.
2. Problems in the Art
In the field of battery charging systems, there are two main types of battery power systems, "smart" batteries and "dumb" batteries. "Dumb" batteries are simply batteries with no processing or memory storage capabilities. In contrast, "smart" batteries include some type of processing or memory storage capability. There are various problems associated with both "dumb" and "smart" battery power systems.
Prior art "dumb" batteries suffer from a number of problems that increase the cost of the device in which the battery is used. Problems with prior art "dumb" batteries include: the lack of acceptable run-time of the device powered by the battery; the lack of acceptable life-span of the battery pack; non-user-friendly batteries (i.e., a need for maintenance of battery packs in order to realize full performance; the need to have a separate charging system for each type of battery; the lack of user feed-back as to the state of the charge, remaining charge life, and other performance criteria; and the need for the user to provide technical assistance when maintaining a battery (i.e., the maintenance functions are not transparent to the user).
In addition to the problems that users face, original equipment manufacturers (OEM) have additional concerns with battery performance including: the inability to determine how old a battery actually is for warranty claims; the inability to determine the number of cycles a battery has gone through; the inability to determine a good battery from a bad battery when a battery is returned by a customer; and the lack of understanding of usage patterns and history which would help the manufacturer to design more robust, cost-effective battery packs.
Prior art "smart" batteries also suffer from a number of problems. Typical prior art smart batteries only provide the benefit of the availability of a "gas gauge" to provide an indication of the charge left in a battery. The importance of such a gauge is only important if the battery life of the device being powered lasts longer than the required work time. In the laptop computer market, for example, users typically never have enough run time. In the cellular and 2 way portable radio markets, users have enough run time most of the time, however this almost always comes with a trade-off, typically size or cost. Also, most battery gas gauges are voltage-dependent making them highly inaccurate.
Many prior art smart systems also do not provide any feedback to the user. Such a system may be performing a valuable service to the user, but with no means of feedback to the user (via an LCD, etc.). Additionally, prior art smart battery approaches have driven the need to put microprocessors inside the battery pack. Putting microprocessors inside a battery pack will increase the cost of the product.